Process of and means for removing sand cores from hollow rolled metals



I C. F. PRESCOTT.

PROCESS OF AND MEANS FOR REMOVING SAND COBES FROM HOLLOW ROLLED METALS.

APPLICATION FILED SEPT. 9. 1915.

L 1,304,200, Patented May 20, ML).

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APPLICATION FILED SEPT. 9. I918 Patented May 20, 1919.

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WI T/VESSES Wax/M A TTOHA/EIS C. F. PRESCOTT. PROCESS OF AND MEANS FOR REMOVING SAND CORES FROM HOLLOW ROLLED METALS.

APPLICATION FILED SEPT. 9. I918.

Patented May 20, 1919.

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/ INVENTOR %Z7 z4 w/L-0 ATTORNEYS UNITED STATES PATENT OFFICE.

1 CHARLES r. rnnscorr, or BROOKLYN, NEW YORK.

PROCESS OF AND MEANS FOR REMOVING SAND CORES FROM HOLLOW ROLLED METALS.

Specification of Letters latent.

Patented May 20, 1919.

Application filed September 9, 1918. Serial No. 253,380..

To all whom it may concern:

Be it known that I, CHARLES F. Pnnsco'rr, a citizen of the United States, and a resident of the city of New York, borough of Brooklyn, in the county of Kings and State of New York, have invented a new and Improved Process of and Means for Removing Sand Cores from Hollow Rolled Metals, of which the following is a full, clear, and exact description.

This invention relates to the art of constructing tubular bars of metal, such for instance as the internal tie bars for steam boilers which are ordinarily rolled from hollow ingots filled with' sand, the sand during the rolling of the bars being fused and formed into elongated cores of relatively 'minute diameter in the finished bars,

and which are required to be removed in order to make the bores of the bars functional.

I am aware thatin the construction of hollow rolled bars it has been proposed heretofore to remove the sand cores from long tubular bars or the like by compressed air, but such previous process has proved in my experience to be too slow to be economical and practicable. By my improvement there fore I provide a means and process for discharging the sand cores from the bores through the action of water or other liquid under tremendous pressure, the liquid acting upon the sand by means of erosion in connection with the physical contact between the nozzle or other-means for delivering liquid under pressure to the sand.

Another object of the invention is to utilize the jetting effect of water delivered through a nozzle or the like through the action of a reciprocating pump having distinct pulsating action due to the reciprocations of the pump, the pulsating action of the stream of water serving in connection with the aforesaid erosive action to materially augment or increase the rapidity of action of my improvement.

With the foregoing and other objects in view the invention consists in the arr. ngement and combination of parts hereinafter described and claimed, and while the invention is not restricted to the exact details of construction disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings, in which like reference characters designate the same parts in the several views, and in which Figure 1 is a side elevation giving a diagrammatic representation of a preferred embodiment of means for carrying out my process.

Fig. 2 is a similar View taken at right angles to Fig. 1, parts of both figures being broken away to conserve vertical space.

Fig. 3 is a vertical transverse sectional detail on'the line 33 of Fig. 2.

Fig. 4 is a. still further enlargement in detail on the line 44 of Fig. 3.

Fig. 5 is a side view of the lower portion of the valve seat plug prior to the attachment of the jet tube thereto.

Fig. 6 is a transverse sectional detail on the line 66 of Fig. 4 indicating the cross tion of the liftlng shoe.

Fig. 10 is va plan view of the lifting shoe with the foot removed; and

Fig. 11 is a horizontal sectional detail through the lifting shoe on the line 1111 of Fig. 2.

Referring now more specifically to the drawings, I show at 15 a vertical casing the length of which for the purpose of explanation may be understood to be approximately seventeen feet for the treatment of hollow rolled bars sixteen feet in length. It is to be understood, however, that any references to specific dimensions are to be taken as illustrative and not as limitations. To the upper end of the casing is secured ahead 16 through valve seat structure projects upward into a passageway 16 of the head 16 and in alinement with a bonnet 20 tapped into the upper portion of the head at 21, said bonnet constituting a guide for the stem 22 of the valve 23 cooperating with the seat 18. Any suitable packing gland 24 serves to prevent leakage around the valve stem. To the upper end of the valve stem is pivoted a rocker 25 to which a depending controlling rod 26 is at tached and leading downward through a guide 27 within convenient reach of the operator, but any other specific type of valve controlling means may be employed.

In the usual process of manufacture of hollow rolled stay bolts a hollow billet is filled with sand and the ends plugged, after which the billet is heated and passed through the rolls to elongate it and reduce its diameter. This rolling action reduces and elongates the hole in the billet and at the same time compacts the sand so that after the bar is finished the removal of the sand core having a diameter of about three sixteenths of an inch is very difficult from a bar sixteen feet long. The jet tube 19, therefore, must be long enough and have a diameter small enough to pass freely through the bore of the bar, fragments of which are indicated at B in Figs. 8 and 9. The outside diameter of the tube 19 in the illustration given should be about one eighth of an inch and with a bore of one sixteenth of an inch extending throughout its entire length of about seventeen feet. Any suitable material may be employed for this tube, but I recommend brass which may be tipped at its lower end with a tool steel nozzle 19 where it is subjected to the most severe erosive action.

The tube 19 being so long, extending throughout the full length of the sectional casing 15, and being so relatively small in diameter requires to be well braced at close intervals within said casing. Any suitable means may be provided to accomplish this bracing effect, but the means I have found to be most suitable consists ofv a series of vertically spaced disks 28 made of any suitable rigid material such as thin sheet metal, each disk having a central hole 28 having slidable fit upon the outer surface of the tube 19. As will be noted the casing 15 is made up of a series of tubular sections connected each to each endwise, each lower section being smaller in diameter than the next section above it. Furthermore each of the several sections is counterbored to form a series of steps or shoulders 29 upon which the several disks 28 are adapted to rest. but from which they are movable upward. Below the lowermost disk 23 is a thimble 30 having a flange 31 at its upper end having the same function as the disks 28 in so far as it acts as a brace for the tube 19 and through which the thimble is adapted to rest upon the main supporting bed plate 32 at the lower end of and supporting the casing 15. The thimble carries within its upper end a plurality of lugs 33 against which the upper end of the bar B is adapted to abut while said upper end is admitted loosely within the main cylindrical portion of the thimble. The lugs 33 insure easy exit for the mixture of water and sand that is delivered from the bore b in the practice of the invention.

The foot 34 is provided with a central bore 35 leading into a pit 36 in the lifting shoe 37, the foot 34 being tapped into the shoe 37. The pit 36 has one or more lateral delivery or drainage openings 38 leading therefrom. The upper end of the bore 35 is flared upwardly at 35 to automatically center and support the lower end of any of a number of different standard sizes of hollow bars B as indicated in Fi 9.

The lifting sfioe 37 is provided on opposite sides of the center with guide holes 39 whereby said shoe is guided in its vertical movements along a pair of parallel guide rods 40 fixed at their upper ends in the bed plate 32, and suitably supported at their lower ends so as to hold them steady and rigid. By this means the shoe 37 is adapted to move in a precise vertical direction carrying with it the bar B from which the sand core is to be removed. The upper end of the bar being projected into the thimble 30 will be held at its upper end from lateral movement by said thimble. Any suitable means may be provided to exert an upward impulse upon the lifting shoe and the bar supported thereon. I have found in practice that an upward thrust of about fifty pounds exerted by the shoe upon that portion of the bar coming into contact with the nozzle end of the jet tube 19 is most efficient, and hence it is desirable to maintain this pressure substantially uniform. To this end I provide automatic weight means acting upon the shoe and its load in the form of weights W attached to a pair of flexible connections 41 leading over a pair of coaxial pulleys 42 just above the bed plate 32, and thence downward to suitable points of connection with the lifting shoe. These connections may be wire cables, chains, or any other suitable means having sufficient strength and of an appreciable weight ac cordingly. The tendency of the weight W as indicated is to over-balance the weight of the shoe and its load to a considerable extent, and therefore with the elevation of the shoe and a corresponding lowering of the weight there is a gradual increase of the actual weight of the weight W due to the excess of the flexible connections on the Weight side of the pulleys 42. It will be observed, however, that with the elevation and then the disks 28 will be successively lifted and carried along the tube 19 upon the thimble so that the disks in addition to their function as bracing means for the tube 19 will act to counter-balance the added effective weight of the counter-weight W due to the excess of the flexible connections. By this means I am able to provide a substantially constant effective weight of the counter-balance W and thereby I hold the bar B elevated with the sand core thereof in direct contact with the nozzle end 19 of the tube 19. The water or other liquid under high pressure from the pump or other source of pressure admitted into the passageway 16 of the head 16 through an inlet 16 will act directly upon the sand core and by the erosive action above referred to will loosen the sand and deliver it upward from the upper end of the bore and downward between the inner wallvof the thimble 30 and the outer surface of the bar B, an operation that is automatic after the pressure liquid is admitted and which is accomplished in a very brief time. When the sand core is completely removed from the bore b the operator will know by delivery of the jet of water directly through the bore 35 of the foot and thence outward through the drainage openings 38. He will then draw downward upon the controlling rod 26 closing the valve 23. On the drawing downward then of the lifting shoe 37 the cleansed bar B will be lowered and removed, the bracing disks 28 will be restored to their normal bracing position as indicated in Figs. 6, 7, and 8, and the weight W will be lifted ready for the subsequent application of a new bar B and repetition of the operation already described.

The jet tube 19 being so slender and relatively delicate demands special means for securing it to the valve plug body 17 at its upper end in order to hold it securely and yet revent any possible crushing, bending, or buckling thereof. To this end, as shown in Figs. 4, 5, and 6 the lower end of the plug 17 is generally cylindrical in form but provided on opposite sides adjacent to its lower end with a pair of parallel kerfs 43 leaving a web or neck portion 44 essentially rectangular in cross section, and in which I form a transverse square hole 45. The plug body is provided with a central bore 17. terminating in a shoulder 46 against which the upper end of the tube 19 abuts, the tube having its axis in the center of the hole 45. I then pour molten solder into the hole 47 filling the same, which when cold makes a positive lock gripping the tube 19, and preventing endwise movement thereof from the plug 17.

I claim:

1. The herein described process of removing the sand core from a rolled bar which consists in projecting a stream of liquid into the bore of the bar, and into direct erosive contact with said core.

2. The herein described process of removing the sand core from a rolled metal bar which includes the delivery under enormous pressure of a pulsating stream of liquid into the bore of the bar against the core.

3. In means for removing the sand core from a long metal bar having a relatively small bore, the same comprising a jet tube longer than the bar and having a diameter smaller than the bore of the bar, means to move the bar and jet tube relatively one over the other to cause the projection of the tube through the bore of the bar with its end in direct contact with the core, and means to project a stream of liquid under enormous pressure through the jet tube.

4. In means for removing the sand core from a long rolled bar having a relatively small bore, the same comprising a jet tube longer than the bar and having an external diameter less than that of the bore aforesaid, means to cause relative movement between the jet tube and the bar to cause the projection relatively of the tube through the bore of the bar, and means to deliver a pulsating current of high pressure fluid through the jet tube in dn'ect contact with the end of said tube against the core.

5. In a device for removing the sand core from a long rolled metal hollow bar, the combination of a tubular casing, a jet tube fixed in and extending along'the interior of the casing, means to project the bar to be cleansed into one end of the casing with the adjacent end of the jet tube entering the bore thereof and in direct contact with the core, automatic means to insure the action of the projecting means at a uniform pressure, and means to deliver under high pressure a flow of fluid through the jet tube into erosive action upon the core as aforesaid.

6. In means for delivering the sand core from a hollow metal bar, said means comprising in combination an upright tubular casing, a series of transverse brace members supported at intervals within and,throughout the length of the casiaig and movable freely from normal position toward the upper end of the casing, a jet tube of smaller external diameter than the bore of the bar and projecting through the centers of said brace members, a lifting shoe supporting the lower end of the bar, and means acting upon the lifting shoe to elevate the same at a uniform pressure, the upper end of the bar coming into the casing and embracing the nozzle end of the tube, said bar and its lifting means acting to lift the brace members successively during the upward movement of the bar.

7. In a device to remove the sand core from a hollow metal bar, the combination of a tubular casing having a succession of stepped shoulders of difi'erent diameters extending throughout its length at intervals, a like series of flat brace members supported upon said shoulders, a jet tube for pressure fluid projecting with a sliding fit through said brace members, a thimble supported upon the lower portion of the casing and constituting an auxiliary brace member for the tube, said thimble being adapted to receive the u per end of the bar to be cleansed, a lifting s oe supporting the opposite end of the bar, and counter-balance means connected to said shoe and operating over overhead guiding means serving to lift the shoe moaaoo and the bar supported thereon at a substantially uniform pressure against the jet tube.

8. In a fluid pressure device for removing the sand core from metal bars, the combination with a fluid pressure head, of a valve seat body fitted therein, a jet tube fitted longitudinally in the block body, said body being formed with a cavity through which the tube extends, a mass of molten metal filling said cavity and surrounding the tube locking the same from endwise movement, and a valve cooperating with the valve seat.

CHARLES R PRESCOTT. 

